Outcomes Research in Children with Hearing Loss: Recommendations

NIDCD Outcomes Research in Children with Hearing Loss
December 12 and 13, 2006
Bethesda, Maryland

Workshop Recommendations

Following are the recommendations in each of the five areas (Outcomes Research—General Issues; Outcomes Research—Hearing Loss in Children Design and Child Factors; Sources of Variance: Family, Child, Treatment, Social; Complementary/Additional Research Needs; and Other Considerations). Consensus statements of participant discussions are incorporated as appropriate.

Section 1. Outcomes Research—General Issues

A general issue concerned funding mechanisms. Basic and applied research with strong theoretical rationales concerning biological, psychological, and/or social mechanisms relevant to outcomes might be funded via an R01 mechanism using CSR standing study sections. Applied research that is more narrowly targeted toward demographic or bigger picture clinical outcomes, however, might need alternate review mechanisms that allow a more focused assessment of clinical relevance and proficiency. A consensus of the Workshop was that both basic and applied research should be encouraged.

Another general issue concerned selection of appropriate experimental cohorts and control groups. Discussions concerned the rationales for targeted issues such as 1) characteristics of loss, i.e., degree, configuration, age of onset, stability, and bilateral or unilateral; 2) presence or absence of multiple handicaps, and 3) characteristics of appropriate control groups, e.g., if children with hearing loss have multiple handicaps, similar handicapping conditions in children without hearing loss are needed. A consensus of the Workshop was that initial research projects might benefit from focusing on outcomes in children with hearing loss without co-morbidity prior to attempting to understand outcomes in children with hearing loss in the presence of other complicating factors.

For national or multi-site clinical studies, a consensus of the Workshop is that experimental cohorts and control groups must be nationally representative. To the extent possible, existing longitudinal datasets should be scrutinized for their value in identifying important confounds and co-variates, sensitive screening markers, patterns of development after identification/intervention, and multidimensional measures that could yield a more sensitive characterization of outcomes “in the whole child” after identification/ intervention. A consensus of the Workshop was that sensitive characterization will require appropriate assessment of multiple dimensions across time.

Another general issue is how to ensure access to a sufficient population given the low incidence of children with hearing loss. This concern is related to the sample size necessary to achieve adequate statistical power. Studies concerned with descriptions of outcomes of hearing loss without regard to intervention will need to find ways of identifying children from population samples rather than clinical referral sources. This may require the development of sensitive screening markers that could be applied to large scale population surveys or the use of ongoing epidemiologic studies of child health where hearing screening is being done. In short, a representative and sufficient sample of children will require appropriate infrastructure. Some members of the Workshop thought the infrastructure of a system that provides comprehensive access to primary service providers might be helpful and were enthusiastic about the possibility of cooperating with State systems to address this possibility. Other members were more guarded in their assessment of the latter's potential. It should also be noted that some existing State systems may not allow researchers to identify children with hearing loss who are successful and don't require assistance.

Another general issue is that outcome studies of health services using observational methods rather than random assignment will need to incorporate a thoughtful model of intervening and confounding variables. Measures of these variables may be challenging. There is a current lack of measures of speech and language services that would reflect quality. A sensitive array of multidimensional variables and appropriate data analytic approaches are critical to the success of any outcome study.

A final general issue is that outcomes themselves need to be well rationalized and viewed within a complex causal structure. What are the multidimensional factors underlying outcomes in communication and quality of life? How is success defined and measured for outcomes? What is the impact of intervention on outcome as a function of child/parental/psychosocial factors and type of intervention, and how is quality of service quantified for different types of intervention? It should be noted that some outcomes such as improved speech and language development may be viewed as more proximal to the basic hearing loss whereas communication functions such as conversational participation or classroom performance may be viewed as more distal and dependent upon speech and language.

Section 2. Outcomes Research: Key Issues in Design and Child Factors

Design. Consideration of the following as relevant

Targeted age range

Age-dependent multifaceted outcome measures

Focus on child and family

Stability of outcome measures

Definition of success

Cohort size

Quality of life

Recruitment, retention, and loss to follow-up

Statistical approaches

Complexities and challenges of multi-center research including individual center compliance, timely submission of quality data, and methods of direct data entry

Child Factors Between Birth to 5 years. Consideration of subset of following as relevant

What are the effects of hearing loss on development for children with and without other disabilities?

What are the effects of socioeconomic and related factors, such as poverty, on outcomes?

What are different developmental trajectories from birth to 3 years of age for language and cognition in children with varying levels of hearing and with unilateral vs bilateral losses compared to typical hearing children?

What is the incidence, family-child characteristics, and developmental course for children with progressive hearing loss?

What is the incidence, family-child characteristics, age of onset, and developmental course for children with delayed onset hearing loss?

Outcome Expectations: Birth to 3 years. Consideration of subset of following as relevant

Based on existing measures, such as those required by the Food and Drug Administration (FDA) HR-QoL (Hearing Quality of Life)

Compliance with World Health Organization models of performance assessment

Correlation with clinical metrics of performance

Section 5. Other Considerations

Standardize testing across agencies and intervention programs

All relevant parties should be encouraged to consider instruments (early language, speech, achievement) that could be recommended for administration at the state level. Considerations should include likely state participants and programs, data collections systems, individual vs. aggregate data, etc.

Facilitate access to data

All relevant parties should be encouraged to create compatible data sets and to make current data sets available as allowed.

Clinical researchers should be encouraged to consider attending Early Hearing Detection and Intervention (EHDI) meetings and developing relationships at the state level with Part C administrators.

All relevant parties should be encouraged to consider mechanisms for following and tracking children across agencies (Health Research Services Administration, Center for Disease Control and Department of Education) over time (State EHDI and Part C birth–3 and Part B 3–21).

Additional considerations for randomized clinical trials and well designed quasi-experimental studies

In addition to the NIDCD, the Department of Education Institute of Educational Sciences also supports and funds studies on intervention.

All relevant parties should be encouraged to consider the desirability of common protocols.

All relevant parties should be encouraged to consider measures similar to those used in other large data sets, such as Early Childhood Longitudinal Study, the Early Childhood Outcomes Study or the National Health and Nutrition Examination Survey.

Federal and State Government

All parties should continue to interact and coordinate at the national, state and local levels.